Septic system filter



FIG. 1 is a perspective view;

FIG. 2 is a front view;

FIG. 3 is a right side view;

FIG. 4 is a back view;

FIG. 5 is a top view;

FIG. 6 is a bottom view; and,

FIG. 7 is an enlarged, fragmentary view of the circled portion in FIG. 3.

The broken line showing is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a septic system filter, as shown and described. 